A thousand-year-old family begins with one fighting against ten thousand.

It was the 8th year of Emperor Jing of Han's reign. Emperor Jing had yet to appoint a crown prince, and Liu Zhi, who was already 5 years old, had shown extraordinary intelligence and talent, which greatly pleased Emperor Jing, who felt that this child was quite like himself.

Princess Guantao in the Jiaofang Palace found Liu Zhi's mother.

"Wang Zhi, would you be willing to form a marriage alliance with me, allowing your son Liu Zhi to marry my daughter? I am willing to fully support him in becoming the crown prince."

Wang Zhi was somewhat tempted; it was the position of Crown Prince.

But did Princess Guantao have this ability?

Since the Wei brothers coerced the harem a few years ago, the harem's influence in the court has become very limited. Even Princess Guantao does not have much influence. Therefore, Wang Zhi has serious doubts about Princess Guantao's promise.

However, she didn't want to offend Princess Guantao, since Princess Guantao had a great influence in the palace, and offending her would mean a difficult future.

Emperor Jing of Han has now shown great favor to his son, Liu Zhi. If he could also gain the help of Princess Guantao, and have her whisper in Empress Dowager Dou's ear, the chances of his son becoming the crown prince would greatly increase.

Unless her son could marry a daughter of the Wei family, nothing could offer him more help than Princess Guantao. Wang Zhi, who had long resided in the palace, understood this very clearly: only one person could ever decide the crown prince—Emperor Jing of Han. The other half was the Wei family, but the Wei family had never participated in the struggle for succession, so there was only one. The opinions of others were not that important.

After careful consideration, Wang Zhi nodded and agreed to Princess Guantao's request.

Meanwhile, a young man, led by Wei Qing, arrived at Weiyang Palace and met Emperor Jing of Han, Liu Qi.

Emperor Jing of Han was somewhat surprised to see that Wei Qing had brought someone with him.

He was also very familiar with this person; he was Wei Qing's second son.

Wei Shou was an eccentric genius who disliked studying literature but preferred studying medicine.

"Grand Minister of Agriculture, what brings you here with Wei Shou?"

Wei Qing took out a memorial and handed it to Emperor Jing of Han.

"This data was obtained by Shou'er after visiting various prominent families, nobles, scholars, and wealthy households in Chang'an."

「近10年来长安城的人数都在15万左右，每年约有1500对新人结婚，而这1500对新人当中有接近10%都是近亲结婚。所谓近亲结婚就是指的三代之内有同一个亲属的人。」

"In the past 10 years, there have been nearly 1500 couples who married close relatives and 13,500 couples who married non-close relatives."

"According to Shou'er's investigation, among these 1500 couples: 250 couples had no children, 800 of the remaining couples had children who died in infancy, and only 450 couples had children who were still alive. Among these 450 couples, 200 of the children had eye diseases, intellectual disabilities, blindness, deafness, or aphasia."

Of the 13,500 couples who married outside their immediate family, almost all of them had children, and the children of 11300 of these couples survived.

"Of these 11,300 couples, only a few hundred had children born with certain diseases," Wei Qingchao explained to Emperor Jing of Han.

Emperor Jing of Han was very sensitive to numbers as he spent many years handling state affairs.

He snatched the memorial from Wei Qing's hand and began to read it himself. It contained a clear record of where every household lived.

Most of them were from prominent families, members of the Liu clan, or wealthy merchants.

If Emperor Jing of Han were willing to investigate, he could easily find out whether these materials were true or false. Therefore, he believed Wei Qing and that he was definitely not lying to him. In other words, consanguineous marriage really had such great harm. No wonder he and Empress Bo had never had any children.

"I see, I see."

For an emperor, the most important thing is the continuation of his lineage;

One requirement was that, as the emperor, he had to have sons, and the more the better.

Secondly, the more offspring the people have, the larger the population and the more resources the country has. Currently, from the Liu imperial family to ordinary people, although there is a custom of not marrying people with the same surname, marriage with close relatives on the maternal side is considered a sign of strengthening ties, so it is very popular.

According to records, during the Han Dynasty, the proportion of consanguineous marriages in the Liu imperial family reached as high as 30%.

It is easy to imagine how prevalent the practice of consanguineous marriage was during the Han Dynasty.

Wei Shou stepped forward and bowed deeply to Emperor Jing of Han: "I beg Your Majesty to issue an edict, for the sake of the imperial family and all the people of the world, to prohibit marriage between close relatives among the people of the world."

Wei Qing also stepped forward and said to Emperor Jing of Han, who was still standing, "Please issue an edict, Your Majesty."

With the clear data before him, Emperor Jing of Han no longer hesitated, but directly ordered an imperial edict to be drafted, clearly proclaiming to the world the dangers of consanguineous marriage.

"Now, a skilled physician of the Wei family has observed that among those who marry within their own blood, 30% are infertile, 60% die young, and of those who survive, half suffer from hidden illnesses. If offspring are not abundant, the foundation of the nation will be shaken. For the sake of the long-term survival of the state and the well-being of the people, this decree is hereby issued:"

Marriage between direct blood relatives within three generations is strictly prohibited; violators will be punished according to the law.

"The marriage ceremony must verify the family genealogy to avoid suspicion of kinship."

"Local officials must strictly investigate marriage households, and those who know about such marriages but fail to report them will be held accountable."

He believed that the powerful families would not oppose the decree, because the continuation of their lineage was of great importance to them as well.

Nobody wants the family business they've worked so hard to build up to be inherited by a fool.

The biggest difference between the Han Dynasty, or rather the entire feudal era, and later dynasties was the distinction between legitimate and illegitimate children.

These marriages between close relatives were mostly for the purpose of strengthening family ties, and therefore the wives were all principal wives.

In the Han Dynasty, the children born to the principal wife were considered legitimate sons, while illegitimate sons had no right to inherit.

Unless the emperor personally issues an edict allowing you to be adopted by his principal wife or by his direct descendants, even if you have a son, he cannot inherit your title and the court's favors unless he is the legitimate son.

Therefore, in ancient times, it was an extremely great favor for the emperor to allow you to be adopted by your brother or for your brother to be adopted by you as his heir.

Huo Guang worked hard for decades, and with the help of assisting the emperor and formulating strategies, he finally fulfilled his wish to have his son adopted by Huo Qubing, so that his deceased brother could have a lineage to carry on.

This was also the reason why many feudal lords in the Han Dynasty died out.

Just look at Prince Jing of Zhongshan. The princes of the Han Dynasty had no shortage of offspring, but many of them died out because they had no legitimate sons.

Now if you tell them that the reason they have no offspring has been found—it's because they married close relatives—wouldn't they be furious?

Princess Guantao, accompanied by Wang Zhi, was on her way to discuss this matter with Emperor Jing of Han when she overheard the entire story. Wang Zhi was horrified; her son was the heir to the throne, how could he have married his own cousin and caused the line to end?

How could a prince without a son be made crown prince?

Absolutely not.